[muska3]

For those on Windows there's Twinkle Tray, works remarkably well. It has the ability to set timers, which I set to dim my monitor at night and increase the brightness during the day.

[voltagex_]

I have 2 Dell monitors and I haven't been able to get this to work either on the built-in Intel graphics or with HDMI plugged into an AMD card.

[thesandlord]

I just tried this with two Dell U2711s connected via DisplayPort to a USB-C adapter[0] and everything is working really well!

I have a laptop with a Ryzen 3 and a 1660ti, so it might be the Nvidia graphics that is enabling this.

[0] https://smile.amazon.com/Cable-Matters-Multiport-DisplayPort...

[muska3]

My setup is an Asus monitor connected to a usb hub using HDMI, and it works wonderfully. I wonder what's causing issues in your chain.